I really appreciate that you actually took the time to look at this, thanks a bunch!
Either way, I'm constantly using Clipboard to debug this thing, and I'm pretty stumped on the outcome - regardless of window state, I only get this:

Left side is the result of SendMessage, right side is a screenshot taken from mIRC.

In case anyone else wants to give it a shot, heres the source:
http://rapidshare.com/files/411579280/m7rc.zip
Simply load the script and /createTwoButtons to see something. Change alias m7rc in case the dll has a different name or is located somewhere else.